Rigid spine syndrome. Some evidence of varying pathological patterns.

Rigid spine syndrome is a rare disorder supposed to be myopathic in origin, its major histologic abnormality being apparently a proliferation of connective tissue. A case of this syndrome observed in a 8-year-old girl with a progressive and rapidly fatal course is reported. Examination of nerve conduction velocity suggested a neurogenic rather than a myopathic impairment. Muscle biopsy disclosed nonspecific findings, such as fibre size variation, few streamings, but no proliferation of connective tissue. A review of the cases presented in the literature let us suppose that this syndrome is a complex clinical disorder probably secondary to varying pathological processes.